Method of manufacturing flexible wiring substrate and method of manufacturing electronic component mounting structure

Abstract

A method of manufacturing a flexible wiring substrate of the present invention includes the steps of preparing a tape-like substrate composed of a resin layer and a reinforcing metal layer provided on its lower surface, then forming a via hole whose depth reaches the reinforcing metal layer by processing the resin layer of the tape-like substrate by the laser, and then forming a wiring pattern which is connected to the reinforcing metal layer through the via hole on the resin layer by the semi-additive process, wherein the reinforcing metal layer is patterned to constitute a connection pad connected to the wiring pattern or is removed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1G are sectional views showing a method of manufacturing a tape package in the prior art;

FIGS. 2A to 2I are sectional views showing a method of manufacturing a flexible wiring substrate according to a first embodiment of the present invention;

FIGS. 3A to 3C are sectional views showing a method of manufacturing a flexible wiring substrate according to a variation of the first embodiment of the present invention;

FIGS. 4A to 4C are sectional views showing a method of manufacturing a first electronic component mounting structure according to a second embodiment of the present invention;

FIG. 5 is a sectional view showing a second electronic component mounting structure according to the second embodiment of the present invention;

FIGS. 6A and 6B are sectional views showing a method of manufacturing a third electronic component mounting structure according to the second embodiment of the present invention; and

FIG. 7 is a sectional view showing a fourth electronic component mounting structure according to the second embodiment of the present invention.

Claims

1. A method of manufacturing a flexible wiring substrate, comprising the steps of: preparing a tape-like substrate composed of a resin layer and a reinforcing metal layer provided on a lower surface of the resin layer;forming a via hole whose depth reaches the reinforcing metal layer, by processing the resin layer of the tape-like substrate;forming a seed layer in the via hole and on the resin layer;forming a resist film in which an opening portion is provided in an area containing the via hole on the seed layer;forming a metal layer from the via hole to the opening portion of the resist film by an electroplating utilizing the seed layer as a plating power feeding layer;removing the resist film; andforming a wiring pattern, which is connected to the reinforcing metal layer through the via hole, on the resin layer by etching the seed layer using the metal layer as a mask.

2. A method of manufacturing a flexible wiring substrate, according to claim 1, wherein after the step of forming a via hole, a pad plating layer is formed on a bottom surface of the first via hole.

3. A method of manufacturing a flexible wiring substrate, according to claim 1, wherein the tape-like substrate is a long one which is pulled out from a reel and is carried in the longitudinal direction.

4. A method of manufacturing a flexible wiring substrate, according to claim 1, further comprising the step of: after the step of forming the wiring pattern,forming a connection pad connected to the wiring pattern on a lower surface side of the resin layer by patterning the reinforcing metal layer.

5. A method of manufacturing a flexible wiring substrate, according to claim 1, further comprising the step of: after the step of forming the wiring pattern,exposing a lower surface of the wiring pattern in the via hole by removing the reinforcing metal layer.

6. A method of manufacturing a flexible wiring substrate, according to claim 1, wherein the via hole is formed by processing directly the resin layer by a laser not to interpose a mask in the step of forming the via hole.

7. A method of manufacturing a flexible wiring substrate, according to claim 1, further comprising the step of: after the step of forming the wiring pattern,forming an n-layered (n is an integer of 1 or more) built-up wiring layer connected to the wiring pattern on an upper surface side of the tape-like substrate by a same method as a forming method of the wiring pattern.

8. A method of manufacturing a flexible wiring substrate, according to claim 1, wherein the resin layer is made of polyimide, and the reinforcing metal layer is made of a copper foil.

9. A method of manufacturing an electronic component mounting structure, comprising the steps of: preparing a tape-like substrate composed of a resin layer and a reinforcing metal layer provided on a lower surface of the resin layer;forming a via hole whose depth reaches the reinforcing metal layer, by processing the resin layer of the tape-like substrate;forming a seed layer in the via hole and the resin layer;forming a resist film in which an opening portion is provided in an area containing the via hole on the seed layer;forming a metal layer from the via hole to the opening portion of the resist film by an electroplating utilizing the seed layer as a plating power feeding layer;removing the resist film;forming a wiring pattern, which is connected to the reinforcing metal layer through the via hole, on the resin layer by etching the seed layer using the metal layer as a mask; andmounting an electronic component connected to the wiring pattern.

10. A method of manufacturing an electronic component mounting structure, according to claim 9, wherein after the step of forming a via hole, a pad plating layer is formed on a bottom surface of the first via hole.

11. A method of manufacturing an electronic component mounting structure, according to claim 9, further comprising the step of: after the step of mounting the electronic component,forming a connection pad connected to the wiring pattern on a lower surface side of the resin layer by patterning the reinforcing metal layer.

12. A method of manufacturing an electronic component mounting structure, according to claim 9, further comprising the step of: after the step of mounting the electronic component,exposing a lower surface of the wiring pattern in the via hole by removing the reinforcing metal layer.